Dihalomethylene-bicyclo(3,3,0) octanes

ABSTRACT

THIS INVENTION RELATES TO COMPOUND OF THE FORMULA:   2-(A=)NORBORNANE   IN WHICH SUBSTITUENT A IS -CX2, WHEREIN X IS CHLORINE OR BROMINE.

United States Patent (3 US. Cl. 260-648 3 Claims ABSTRACT OF THEDISCLOSURE This invention relates to compounds of the formula:

in which substituent A is CX wherein X is chlorine or bromine.

CROSS REFERENCES TO RELATED APPLICATIONS This application is a divisionof application Ser. No. 554,231, filed Mar. 11, 1966, now US. Pat. No.3,422,- 155, which is in turn a continuation-in-part of application Ser.No. 254,575, filed Jan. 29, 1963, now abandoned.

It is known that cyclic alkenes, such as cyclohexane, form 1:1 additionproducts with various reactive compounds. For example, the reaction ofcyclohexane with carbon tetrachloride produces1-trichlorornethyl-2-chlorocyclohexane. It would be expected, therefore,that compounds such as 1,5 cyclooctadiene would produce a mixture of 1:1and 1:2 adducts having similar structures.

It has been found, however, the 1,5-cyclooctadiene does not undergosimple addition reactions in many instances, and that the reaction of1,5-cyclooctadiene with polyhaloalkanes results in a transannularrearrangement to produce bicyclo[3.3.0]octane derivatives.

The bicyclo[3.3.0]octane derivatives to which this invention relates andwhich are produced as a result of the reaction of 1,5-cyclooctadienewith polyhaloalkanes can be represented by the formula:

where A is CX or CX R, X being halogen and R being an alkyl radical. Thesubstituent B in the foregoing formula is either halogen or hydrogen.

Among the polyhaloalkanes which react with 1,5-cyclooctadiene to producethe aforesaid compounds are tetrahalomethanes, for example, carbontetrahalides such as carbon tetrachloride and carbon tetrabromide;trihalomethanes, including haloforms such as chloroform and bromoform;and alkyl haloforms such as alkyl chloroforms and alkyl bromoforms, thealkyl groups being typically methyl, ethyl, and propyl, although otheralkyl haloforms, for example, those having alkyl groups of up to about12 carbon atoms or more, may also be employed. Also included within thescope of the invention are mixed polyhaloalkanes in which the halogensare different,

Patented June 15, 1971 for example, such compounds aschlorotrifiuoromethane,

dichlorodifluoromethane and trichlorobromomethane.

The reaction of tetrahalomethanes with 1,5 cyclooctadiene producescompounds having the formula:

where X is halogen. As can be seen, one of the halogens from thetetrahalomethane is attached to the bicyclo- [3.3.0] octane nucleus inthe 6-position and a trihalomethyl radical is attached in the2-position.

The product of the reaction utilizing a trihalomethane has the followingformula:

(IJHa where X is halogen. In this instance, the hydrogen is attached tothe 6-position of the bicyclo[3.3.0]octane nucleus, and again atrihalomethyl group is attached at the 2-position.

When an alkyl trihalomethane, i.e., an alkyl haloform,

is employed, however, the reaction results in products of the followingformula:

where X is halogen and R is the alkyl radical. In this instance again ahalogen is attached to the 2-position and on alkyl dihalomethyl radicalis attached to the 6-position.

In each of the above instances, products of similar structure areobtained when mixed polyhalomathanes are employed, i.e.,polyhalomethanes in which different halogens are attached to the samecarbon. Thus, in the formulas set forth each X ray represent a differenthalogen.

The reaction conditions used to produce the bicyclo[3.3.0]octanederivative from the polyhalomethane and 1,5-cyclooctadiene are notcritical. For instance, no solvent is necessary, although one can beemployed if desired. Similarly, the ratio of reactants does not affectoperability of the reaction, although better yields are obtained if anexcess of the polyhalomethane is present. It is for this reason that asubstantial stoichiometric excess of the polyhalomethane is ordinarilyutilized; usually at least about 5 moles of polyhalomethane per mole of1,5- cyclooctadiene is employed.

In general, the reaction should be carried out utilizing conditions atwhich free radical-catalyzed additions take place. A catalyst as such isnot always necessary, but when a catalyet is not employed, elevatedtemperatures, C. or higher, and preferably to 250 C., should beemployed. Alternatively, a free radical-producing catalyst may beutilized. Among the catalysts which are often used are peroxides such asbenzoyl peroxide and di(tertiary butyl)peroxide, are compounds such asazobis- (isobutyronitrile), ultraviolet light, ferric chloride, andsimilar known free radical-producing catalysts. The amount of catalystis not critical, but the reaction is usually carried out using at leastabout 0.02 mole percent catalyst, based on 1,5-cyclopentediene, althoughhigher or lower amounts can be employed if desired.

When a catalyst is present, the preferred temperature is that at whichthe catalyst yields free radicals at an appreciable rate. Thistemperature varies with the particular catalyst, for example, usingbenzoyl peroxide the temperature should be 70 C. or higher withazobis(isobutyronitrile) 50 C. or higher; with di(tertiary butyl)peroxide, 120 C. or higher; while with ultraviolet light roomtemperature is often satisfactory.

In crop culture, the condition and quality of soil is of utmostimportance. Since nitrogen is necessary for plant growth, and since acommon pathway of nitrogen assimilation of plants is through roots inthe soil, adequate provision of nutrient nitrogen for plant growth mustbe made in the soil. Furthermore, it is necessary to provide favorablesoil environment around plant roots, such as freeing the soil fromsoil-dwelling nematodes, fungi and bacteria.

The provision of supplying nutrient nitrogen is one of the foremostagronomic problems. The nitrogen in the soil is found to occur primarilyin three forms: organic nitrogen, ammonium nitrogen, and nitratenitrogen, of which ammonium nitrogen and nitrate nitrogen are theprimary forms utilized by plants. This nitrogen is absorbed by plants insolution from the soil in the form of ammonium ions and nitrate ions.

The ammonium nitrogen in the soil is derived from bacterial conversionof organic nitrogen or from the added reduced nitrogen fertilizers, suchas anhydrous ammonia, aqueous ammonia, ammonium phosphate, ammoniumnitrate and ammonium sulfate. These ammonium compounds or inorganicreduced nitrogen compounds are readily soluble in water or aqueous soilmedium.

The nitrite and nitrate nitrogen in the soil are derived from theoxidation of ammonium nitrogen by soil bacteria, or by the addition ofinorganic nitrate fertilizers, such as ammonium nitrate, sodium nitrate,potassium nitrate and calcium nitrate. The process of oxidizing ammoniumnitrogen to nitrite ion is carried out by certain soil bacteria and isknown as nitrification. Nitrobacter organisms take over and convertnitrite to nitrate. The ionorganic nitrate compounds are also readilysoluble in water and other aqueous soil mediums. When so dissolved, thenitrate nitrogen largely exists as the nitrate ion.

Because of the anionic nature of this ion, nitrate nitrogen is notadsorbed by soil colloids. Accordingly, the nitrate nitrogen is rapidlyleached by rainfall and irrigation, and readily lost from feeding someof the plants. Further, the nitrate nitrogen is reduced by many soilbacteria, to gaseous volatile nitrogen oxides and to nitrogen gas. Thelatter process is known as denitrification and accounts for anadditional loss of large quantities of nitrate nitrogen from the soil.The yearly loss from leaching and denitrification amounts to from 20 to80 percent of the nitrate nitrogen found in the soil, whatever theanions source.

The tremendous losses of soil nitrogen initiated by the rapidnitrification of ammonium nitrogen, and the leaching and bacterialdenitrification of nitrate nitrogen, have depleted many agriculturaloils of the nitrogen reserve and nitrogen requirements for plantnutrition. In order to replenish the soil nitrogen, the agriculturalisthas resorted to the use of large amounts of synthetic nitratefertilizers and reduced nitrogen fertilizers. In many instances,multiple fertilizer treatments during the growing season have beenrequired to maintain the nitrogen requirements for plant growth. In thispractice, the greater proportion of the employed fertilizers is in theform of reduced nitrogen fertilizers. By the expression reduced nitrogenfertilizers is meant fertilizers containing nitrogen in the reducedstate, and is inclusive of ammonium salts, ammonia; and alsowater-soluble organic compounds readily convertible in soil to ammoniaor ammonium ions, such as urea and cyanamide.

An object of this invention is the provision of a new and improvedmethod of suppressing the loss of ammonium nitrogen from soil. Anadditional object is the provision of a new and improved method forsuppressing the rapid nitrification of ammonium nitrogen in soil suchthat the product is not lost to the plant either through denitrificationor leaching. A further object is the provision of a method of improvingsoil environment of plant roots by the fumigation and disinfection ofsoil, infected with bacteria and fungi (microorganisms that do notenhance or promote plant growth) which attack plant roots.

By the practice of this invention, the nitrification of reduced orammonium nitrogen in the soil to nitrate nitrogen is suppressed, therebypreventing the rapid loss of ammonium nitrogen from the soil. Inaddition, by the practice of this invention, the control of soilinhabiting organisms such as bacteria and fungi may be achieved.

The provision of an effective amount of a novel dihalomethylenebicyclo[3.3.0]octane in the soil or growth medium, or amount sufficientto suppress nitrification or control soil dwelling organisms(parasiticidal dosage) is essential for the practice of the presentinvention. In general, good results are obtained when the growth mediumis supplied with the bicyclooctanes in the amount of from 2 to 250 partsby volume per million parts by volume of medium. The preferred amount isconsider to be from 5 to 50 parts by volume per million parts by volumeof soil. In field applications, the compounds may be distributed in thesoil in the amount of at least 0.25 pound per acre, and through suchcross-section of the soil as to provide for the presence therein of aneffective concentration of the agent. It is usually preferred that thecompounds be distributed to a depth of at least 2 inches below the soilsurface, and at a dosage of at least 0.5 pound per acre inch of soil. Bydispersing very large dosages in growth media, a prolonged inhibition ofnitrification may be obtained over a period of many months. Suchapplication also provides more favorable growth media by freeing thesoil from the organisms attaching plants and plant roots andcontributing to adverse effects on plant growth. The concentration ofthe active compounds is eventually reduced to a minimum by decompositionin the soil.

In one embodiment of the present invention, the novel octanes aredistributed throughout the growth media prior to seeding ortransplanting the desired crop plant.

In another embodiment, the soil in the root zone of growing plants istreated with the novel octanes in an amount sulficient to inhibitnitrification and free the soil of bacteria and fungi but sublethal toplant growth. In such operations, the compounds should be supplied inthe soil in an amount no greater than about 250 parts by volume permillion parts by volume of the soil. By following such practice, noadverse effect is exerted by the compounds upon growth of seeds orplants. Oftentimes it is desirable to treat the soil adjacent to plants,and this procedure may be carried out conveniently in side-dressmgoperations.

In a further embodiment, soil may be treated with the novel octanesfollowing harvest, or after following to free soil of plant attackingorganisms, to prevent rapid loss of ammonium nitrogen and to build upthe ammonium nitrogen formed by conversion of organic nitrogencompounds. Such practice provides favorable growth media and conservesthe soil nitrogen for the following growing season.

In an additional embodiment, the soil is treated with the novel octanesin conjunction with the application of reduced nitrogen fertilizers. Thetreatment with the octanes may be carried out prior to, subsequent to,or simultaneously with the application of fertilizers. Such practiceprevents the rapid loss of the ammonium nitrogen added as fertilizer andthe ammonium nitrogen formed from the organic reduced nitrogen infertilizers by the action of soil bacteria. The administration to thesoil of the octane compounds in an ammonium nitrogen fertilizercomposition constitutes a preferred embodiment of the present invention.

The required amount of the compounds may be supplied to growth media infrom 1 to 50 gallons of organic solvent carrier, in from 1 to 27,000 ormore gallons of aqueous carrier or in from about 10 to 2,000 pounds ofsolid carrier per acre treated.

The concentration of the compounds in compositions to be employed forthe treatment of growth media is not critical and may vary considerablyprovided the required dosage of effective agent is supplied thereto. Theconcentration of the octanes may vary from 0.001 percent by volume to 95percent by volume of the composition, depending on whether thecomposition is a soil treating composition or a concentrate compositionand whether it is in the form of a solid or a liquid. In aqueous liquidtreating compositions, concentrations of from 0.001 percent to 10percent by volume of the octanes is considered the preferredcomposition. The concentration of the octanes in organic solvents may befrom 2 to 90 percent by volume. Solid compositions generally containfrom 5 to 50 percent by volume of the octane. Soil treating compositionsusually contain 0.004 percent to 10 percent by volume of the octanes. Incompositions to be employed as concentrates, the octane is oftentimespresent in a concentration of from 2.5 to 95 percent by volume.

Liquid compositions containing the desired amount of the compounds maybe prepared by dispersing the agents in one or more liquid carriers suchas water and organic solvents with or without the aid of a suitablesurfaceactive dispersing agent or emulsifying agent. Suitable organicsolvents include acetone, diisobutylketone, methanol, ethanol, isopropylalcohol, diethyl ether, toluene, methylene chloride, chlorobenzene andthe petroleum distillates. The preferred organic solvents are thosewhich are of such volatility that they leave little permanent residue inthe soil. When the solutions of active compounds in organic solvents areto be further diluted to produce aqueous dispersions, the preferredsolvents include acetone and the alcohols. When the liquid carrier isentirely organic in nature, particularly desirable carriers are thepetroleum distillates boiling almost entirely under 400 F. atatmospheric pressure and having a flash point above about 80 F.

Dispersing and emulsifying agents which may be employed in liquidcompositions include condensation products of alkylene oxides andphenols and organic acids, alkyl aryl sulfonates, polyoxyalkylenederivatives of sorbitan esters, complex other alcohols, mahogany soapsand the like. The surface-active agents are generally employed in theamount of from 1 to 20 percent by weight of the combined weight ofoctanes and surface-active agent.

Solid compositions containing the active octane may be prepared bydispersing the compounds in finely divided inert solid carriers such astalc, chalk, gypsum, vermiculite, bentonite and the like, fullers earth,attapulgite and other clays, various solid detergent dispersing agentsand solid fertilizer compositions. In preparing such compositions, thecarrier is mechanically admixed with the octane liquid or wet with asolution thereof in a volatile organic solvent. Depending upon theproportions of ingredients, these compositions may be employed withoutfurther modification or be considered concentrates and subsequentlyfurther diluted with solid surface-active dispersing agent, talc, chalk,gypsum or the like to obtain the desired treating composition.Furthermore, such concentrate compositions may be dispersed in waterwith or without added dispersing agent or agents to prepared aqueoussoil treating compositions.

Soil treating compositions may be prepared by dispersing the octane infertilizers such as ammonium fertilizer or organic nitrogen fertilizer.The resulting fertilizer compositions may be employed as such or may bemodified such as by dilution with additional nitrogen fertilizer or withinert solid carrier to obtain a composition containing the desiredamount of active agent for treatment of soil. Further, an aqueousdispersion of the octane fertilizer composition may be prepared andadministered to the growth medium. Fertilizer compositions comprisingthe octane in intimate admixture with ammonium fertilizers constitutepreferred embodiments of the present invention. In fertilizercompositions comprising a reduced nitrogen fertilizer, it is desirablethat the octanes be present in an amount of at least 0.3 percent byweight based on the weight of the nitrogen present in the fertilizer asreduced nitrogen. Thus, when a fertilizer composition contains bothreduced nitrogen and other forms of nitrogen such as in the case ofammonium nitrate fertilizer compositions, the amount of the octane isbased on the weight of the nitrogen present in the ammonia component.

In operations carried out in accordance with the present invention, thesoil may be impregnated in any convenient fashion with the activecompounds or a composition containing these agents. For example, thesemodified or unmodified compositions may be simply mechanically mixedwith the soil, applied to the surface of soil and thereafter dragged ordisced into the soil to a desired depth; transported into the soil witha liquid carrier such as by injection, spraying or irrigation. When thedistribution is carried out by introducing the compounds in the wateremployed to irrigate the soil, the amount of water is varied inaccordance with the moisture content of the soil in order to obtain adistribution of the compounds to the desired depth. The compounds may bereadily and conveniently distributed to a depth of from two to four feetby irrigation methods. The preferred methods embrace procedures usingany of these steps wherein the compounds are distributed in the soilsubstantially simultaneously with a reduced nitrogen fertilizer.

The following examples illustrate the invention but are not to beconstrued as limiting.

EXAMPLE 1 Reaction of 1,5-cyclooctadiene and carbon tetrachloride Amixture of 325 grams of 1,5-cyclooctadiene, 21.8 grams of benzoylperoxide and 3 liters of carbon tetrachloride was refluxed for two days,an additional 14.5 grams of benzoyl peroxide was added and the mixturewas refluxed for an additional 1.5 days. Most of the excess carbontetrachloride was then removed by distillation, the residue wasdissolved in ethyl ether and washed with aqueous sodium bicarbonate.After the ether was evaporated off, the remaining mixture was distilledand the main fraction obtained was redistilled, whereby there wereobtained 283 grams of a fraction boiling at 87 C. at 0.10 millimeterpressure to 90 C. at 0.13 millimeter pressure. This product wasidentified as pure Z-trichloromethyl-6-chlorobicyclo[3.3.0]octane,having the structure:

Analysis.Calculated for C H Cl (percent): C, 41.23; H, 4.62; Cl, 54.13.Found (percent): C, 41.27; H, 4.89; Cl, 53.84.

In addition to chemical analysis, the product was identified by gaschromatographic analysis, which showed essentially one compound; byinfrared analysis which showed only two bands in the 3.4 micron regionand no bands at wavelengths lower than 5.40 microns; 'by proton magneticresonance analysis; and by its chemical behavior in characterizingreactions.

EXAMPLE 2 The same product as in Example 1 was produced by refluxing amixture of 27 grams of 1,5-cyclooctadiene,

milliliters of carbon tetrachloride, 73 milliters of isopropyl alcoholand 1 gram of ferric chloride hexahydrate for 36 hours. After washingthe mixture with water and evaporating the organic layer, 54 grams of aliquid were obtained which was distilled, whereby there was obtained45.4 grams of 2-trichloromethyl-6-chlorobicyclo[3.3.0] octane.

EXAMPLE 3 Reaction of 1,5-cyclooctadiene with chloroform A mixture of108 grams of 1,5-cyclooctadiene, 4.9 grams of benzoyl peroxide and 1liter of chloroform was refluxed for 5 days with additions onconsecutive days of four 2.4 gram portions of benzoyl peroxide, thusmaking the total amount of peroxide used 14.5 grams. Distillation of thereaction mixture yielded 74 grams of a liquid which was redistilledseveral times. There was obtained 30.0 grams of a fraction boiling at110 C. to 111 C. at 9 millimeters pressure, identified as pure2-trichloromethylbicyclo[3.3.0] octane having the structure:

(IJCIa It was identified by its infrared spectrum, its nuclear magneticresonance spectrum and its gas chromatogram, as well as by chemicalanalysis.

Analysis.Calculated for C H Cl (percent): C, 47.49; H, 5.75; CI, 46.74.Found (percent): C, 47.19; H, 5.42; CI. 46.45.

EXAMPLE 4 Reaction of 1,5-cyclooctadiene with bromotrichloromethane Amixture of 27 grams of 1,5-cyclooctadiene, 3 grams of benzoyl peroxideand 148.5 grams of bromotrichloromethane was heated slowly to 75 C.whereupon an exothermic reaction occurred and the temperature rose to114 C. The mixture was maintained at 80 to 90 C. for 24 hours, afterwhich the excess bromotrichloromethane was distilled off and the residuedistilled. There was obtained 54 grams of crude product comprising amixture of 2-trichloromethyl-6-bromobicyclo(3.3.0)octane andZ-bromodichloromethyl-6-chlorobicyclo(3.3.0)octane, having the followingstructures:

(ECla and EXAMPLE 5 Reaction of 1,5-cyclooctadiene with carbontetrabromide A mixture of 22.4 grams of l,3-cyc1ooctadiene and 275.4grams of carbon tetrabromide was heated to 75 C. and stirred andirradiated at this temperature for 2 days under ultraviolet light from asunlamp. After the excess carbon tetrabromide had been removed, thereremained a residue comprising crude2-tribromomethyl-6-bromobicyclo(3.3.0)octane, which tended to decomposeupon further distillation.

8 EXAMPLE 6 Reaction of 1,5-cyclooctadiene with methyl chloroform It hasbeen further found that the foregoing products can be hydrolyzed toproduce compounds in which the trihalomethyl group is converted to adihalomethylene group. Such dihalomethylenebicyclo(3.3.0)octanes havethe formula:

C ClzCHa where X is halogen. In addition, the hydrolysis produces thecorresponding acid in which the trihalomethyl substituent is replaced bya carboxyl radical. The hydrolysis is particularly easily accomplishedin the case of the products obtained from trihalomethane. The hydrolysisreaction requires the presence of a strong acid, and is usually carriedout by reacting the bicyclo(3.3.0)0ctane derivative with an aqueoussolution of the acid. Among the acids which are thus employed arephosphoric acid and sulfuric acid, which are preferred, and nitric acid,which due to its oxidizing properties is less desirable since it maytend to engage in side reactions, thus reducing the yield of the desiredproduct. The example below illustrates the ease and efficiency withwhich the dihalomethylene derivatives and acids are produced.

EXAMPLE 7 Hydrolysis of 2-trichloromethy1bicyclo 3 .3 .0) octane Amixture of 111 grams of 2-trichloromethy1bicyclo (3.3.0)octane, producedas in Example 3 above, and 300 24 hours. The mixture was cooled, dilutedwith water, extracted with ether and the resulting extract separatedmilliliters of percent phosphoric acid was refluxed for into acidic andneutral fractions with aqueous sodium bicarbonate. The neutral fractionwas distilled and gave 29.5 grams of a fraction boiling at 107 C. to 119C. at 15 millimeters pressure. After redistillation this fraction wasidentified as 2-dichloromethylenebicyclq(3.3.0)octane of the structure:

Analysis.-Calculated for C H Cl (percent): C, 56.56; H, 6.33; CI, 37.11.Found (percent): C, 36.76; H, 6.42; CI, 35.26.

Distillation of the acid fraction gave 29.4 grams of exe,cis-bicyclo(3.3.0)octane-2-carboxylic acid of the structure:

It had a boiling point of 89 C. at 0.1 millimeter pressure.

Analysis.Calculated for C H O (percent): C, 70.10; N, 9.13. Found(percent): C, 70.61; H, 9.00.

In these and other tests, various products corresponding to the formulasdisclosed above were produced using varying reaction conditions andcatalysts, and with reactants of different types within the classdescribed.

In addition to providing an advantageous route to the correspondingacids and the dihalomethylene derivatives, 9 as illustrated above, thecompounds of this invention can be used for other purposes. For example,they are useful as plasticizers for resinous compositions, beinghigh-boiling liquids of high halogen content. When used in this manner,they aid in imparting fire retardancy in addition to their plasticizingproperties. They are also valuable chemical intermediates and can beused to produce insecticidal and biologically active materials, forexample, through reduction or dehydrohalogenation reactions. Thedihalomethylene compounds themselves are excellent pesticides. Forinstance, 2-dichloromethylenebicyclo[3.3.0]octane is an effectivefungicide and miticida. In one test illustrating its utility in thisregard, concentrations of 2-dichloromethylenebicyclo[3.3.0]octane as lowas .01 percent prevented germination of Monilia fructicola, the casualorganism of brown rot of stone fruit. It has also been shown effectiveagainst other fungi such as Alternaria solani and against mites such asthe spotted spider mite (Tetranychus telaerius).

EXAMPLE 8 One tenth milliliter of2-trichloromethyl-6-chlorobicyclo[3.3.0]octane was employed as thecandidate bactericide against a pure culture of Nitrosomonse europaes, abacterium known to oxidise ammonium ion to the nitrite The culturemedium was prepared as follows:

Na HPO -13.5 g.

KH PO 0.7 g. MgSO -7H O-0.l g. NaI-ICO 0.5 g. (NH SO -2.5 g. FaCl -6HO14.4 mg. CaCl -2H O--18.4 mg. Distilled water-1000.0 ml. Final pH, 8.0

Aliquots of 100 ml. of the foregoing prepared medium were placed inflasks, sealed, inoculated equally with the M. europaes bacterium, and aminimum time of about 6 days permitted to elapse to permit relativelyprofuse development of the bacterium. The candidate bactericides of 0.1ml. volume was then added to the flasks. The inoculated flasks wereincubated at 28 C. on a rotary shaker for six days, and then wereanalysed quantitatively for nitrite content.

In a check operation, other flasks were prepared in the identicalmanner, omitting inoculation with a bactericide.

Nitrite ion is the particular product of the oxidation of ammoniumnitrogen by N. europaes. Nitrite ion was determined using theGrises-Ilsevay reagent, and a Klett Summerson colorimeter.

10 Percent inhibition of nitrite production was calculated as follows:

Percent Inhibition Nitrite produced in presence of candidate bactericideNitrite produced in absence of candidate bactericide The resultsobtained in testing 2-trichloromethyl-6- chlorobicyclo[3.3.0]octaneindicated 94% inhibition of ammonium nitrogen oxidation to nitrite. Withthe check flasks, there was no inhibition of ammonium ion oxidation.

Workers in the microbiological art have long experienced difliculty inisolation of nitrifying bacteria, particularly in the isolation of thegenus Nitrosomonas in pure culture. The availability of the bacterium inpure form greatly aids in conducting the measurements employed in thecurrent determinations. The pure culture of Nitrosomonas europaesemployed herein, were prepared according to the teaching of Lewis andFramer, reported at J. of Bacteriology, 76, pp. 324-328 (1958).

According to the provisions of the patent statutes, there are describedabove the invention and what are now considered to be its bestembodiments, However, within the scope of the appended claims, it is tobe understood that the invention may be practiced otherwise than asspecifically described.

What is claimed is:

1. A compound of the formula:

wherein X is chlorine or bromine.

2. A compound as in claim 1 wherein X is chlorine. 3. A method ofproducing a compound of the formula:

wherein X is chlorine or bromine, which comprises reacting a compound ofthe formula:

in which substituent A is a radical selected from the class consistingof --CX and CX R, wherein X is chlorine or bromine and R is alkyl andsubstituent B is selected from the class consisting of chlorine orbromine and hydrogen, with an aqueous solution of an acid selected fromthe group consisting of phosphoric acid, sulphuric acid and nitric acid.

References Cited UNITED STATES PATENTS 3,422,155 1/ 1969 Dowbenko260648C DANIEL D. HORWITZ, Primary Examiner U.S. Cl. X.R.

